Dry battery



p 1929- s. L. CASELLA 1,726,540

DRY BATTERY Filed Sept. 23, 1927 i INVENTOR CM Mfg.

Patented Sept. 3, 1929.

UNITED": STATES "1,726,540 PATENT OFFICE.

I SECONDO L. CASELLA, OF NEW YORK, N. Y., ASSIGNOR, IBY MESNE ASSIGNMENTS, 'I'O BOND ELECTRIC CORPORATION, 01? JERSEY CITY, NEW JERSEY, A CORPORATION I OF DELAWARE.

DRY BATTERY.

Application filed September 23, 1927. Serial No. 221,434.

This invention relates to dry batteries containing a so-ca1led bobbin consisting of a Cylindrical mass of depolarizing vmaterial molded about a carbon rod which is adapted 5 to function as the positive electrode of a battery cell. I

In bobbins of the above type, as heretofore made, the depolarizing material is extremely fragile, even though subjected to a considerable amount of pressure in the molding operation, and is liable to partially disintegrate or flake off, particularly at or in the vicinity of the sharp lower edge, regardless of how carefully and'delicately the bobbin is handled during the assembling of the battery. And it has been generally appreciated that broken off particles of depolarizing material are likely to find their way through the electrolyte and work into contact with the zinc or negative electrode of the cell, and thereby establish an internal short Circuit which reduces the shelf life of the cell and brings about other undesirable and detrimental re sults.

To. guard against such internal short circuiting by loose or disintegrated particles of depolarizing materiah it has been Customary to enclose the molded depolarizing material in an envelope such asa wrapping of gauze or a Coating of other perforate material, which effectively prevents disintegration of the bobbin during the assembling of the battery. Such coverings, of course, involve considerable expense, and they are otherwise unsatisfactory from a manufacturing standpoint. v

The general object of this invention provide a dry batterycontaining a naked bobbin so constructed asto obviate the likelihood. 40 of particles of {depolarizing material being broken away from the molded mass of suc material during handling, thus avoiding the necessity for any coveringmeans, and thereby reducing the cost of dry cell manufacture without increasing the likelihood of internal short-circuiting.

The invention will be understood from the following description taken in connection with the accompanying drawing in which a dry battery embodying the invention is shown in a vertical central sectional elevation.

In the drawing the usual zinc containeris indicated as having a cylindrical side or wall 2 and a bottom 3 soldered thereto. The bobis to bin is shown as including a carbon rod 5 having a metal cap 6, and a cylindrical body of depolarizing material 7 molded about said rod and having its lower edge beveled as indicated at 8. This bobbin is naked, that is, the surface of the depolarizing material 7 is left uncovered. In making the bobbin, the beveled edge 8 may be formed during the moldlng operation, or may be. formed by a cutting operation in the manner described in my Co-pending application, Serial No. 211,106, filed August 6, 1927, or may be formed in .any other suitable manner. In order tomake sure that the surface of the molded depolarizing material is free of loose particles, before the bobbin is introduced into the zinc container, the surface of the cylindrical mass is preferably subjected to an a1r blast, for example, in the manner descrlbed in the application just mentioned, before the battery is assembled- Thebobbin is spaced and insulated from the bottom 3 of the zinc container, by a disc 10 of insulating material such as cardboard; and the bobbin 1s spaced and insulated from the cylindrical slde 2 of the container, by rubber bands 12 which are applied to the cylindrical surface of the molded depolarizing material 7 before the battery is assembled. The usual'electrolyte is indicated at 13, and the cell is sealed by the usual sealing material 15 interposed between the top portion of the carbon rod 5 and the wall 2 of the zinc container, and above a washer 16 of cardboard or other suitable material.

In assembling the battery cell,-the bottom 3 of the zinc container is covered by the insulating disc 10, and the appropriate amount of electrolyte 13 is pouredin; whereupon the bobbin is inserted in the container and forced h into the position shown. During this operation, a large portion of the electrolyte 13 is displaced from the bottom of the container into the positionshown in the drawing'in which it surrounds the bobbin. Owing to the beveled edge 8 of the bobbin, and the fact the surface of the molded depolarizating mixture is free of loose particles, this operation takes place substantially without dantger that particles of: depolarizing mixture will be broken off and left in the electrolyte free to make an internal short circuit, the 'attainment of this desirable result being also facilitated by the rubber bands '12 whichkeep the molded depolarizing material from em a bobbin having a rod surrounded by a naked gaging the side of the container during insercylindrical mass of depolarizing material 15 tion of the bobbin. After the bobbin is inhaving its surface free of loose particles and serted in the container, the washer 16 may be ha'ving a beveled lower edge,insu1atingmeans 5 forced down over the top 60f the carbon rod for spacing the end of the rod and end and. 5 into the position shown; and the sealing side of said bobbin from the bottom and side material 15 may be then applied. Except of said zine container, an electrolyte between 20 for the addition of'the usual carboard coversaid bobbin. and said zinc container, and ing (not shown) around the cylindrical side means for sealing the space between the top 10 2 of the zinc container, the battery cell is now of said container and said bobbin rod.

complete. i In testimony whereof I have aflixed my What I claim is: signature to this specification. A dry battery comprising a zinc container, SECOliDO L. CASELLA. 

